/* ***************************************************************************
 *
 * ftbdf.h
 *
 * FreeType API for accessing BDF-specific strings (specification).
 *
 * Copyright (C) 2002-2021 by
 * David Turner, Robert Wilhelm, and Werner Lemberg.
 *
 * This file is part of the FreeType project, and may only be used,
 * modified, and distributed under the terms of the FreeType project
 * license, LICENSE.TXT.  By continuing to use, modify, or distribute
 * this file you indicate that you have read the license and
 * understand and accept it fully.
 *
 */


#ifndef FTBDF_H_
#define FTBDF_H_

#include <freetype/freetype.h>

#ifdef FREETYPE_H
#error "freetype.h of FreeType 1 has been loaded!"
#error "Please fix the directory search order for header files"
#error "so that freetype.h of FreeType 2 is found first."
#endif


FT_BEGIN_HEADER


/* *************************************************************************
 *
 * @section:
 * bdf_fonts
 *
 * @title:
 * BDF and PCF Files
 *
 * @abstract:
 * BDF and PCF specific API.
 *
 * @description:
 * This section contains the declaration of functions specific to BDF and
 * PCF fonts.
 *
 */


/* *************************************************************************
 *
 * @enum:
 * BDF_PropertyType
 *
 * @description:
 * A list of BDF property types.
 *
 * @values:
 * BDF_PROPERTY_TYPE_NONE ::
 * Value~0 is used to indicate a missing property.
 *
 * BDF_PROPERTY_TYPE_ATOM ::
 * Property is a string atom.
 *
 * BDF_PROPERTY_TYPE_INTEGER ::
 * Property is a 32-bit signed integer.
 *
 * BDF_PROPERTY_TYPE_CARDINAL ::
 * Property is a 32-bit unsigned integer.
 */
typedef enum BDF_PropertyType_ {
    BDF_PROPERTY_TYPE_NONE = 0,
    BDF_PROPERTY_TYPE_ATOM = 1,
    BDF_PROPERTY_TYPE_INTEGER = 2,
    BDF_PROPERTY_TYPE_CARDINAL = 3

} BDF_PropertyType;


/* *************************************************************************
 *
 * @type:
 * BDF_Property
 *
 * @description:
 * A handle to a @BDF_PropertyRec structure to model a given BDF/PCF
 * property.
 */
typedef struct BDF_PropertyRec_ *BDF_Property;


/* *************************************************************************
 *
 * @struct:
 * BDF_PropertyRec
 *
 * @description:
 * This structure models a given BDF/PCF property.
 *
 * @fields:
 * type ::
 * The property type.
 *
 * u.atom ::
 * The atom string, if type is @BDF_PROPERTY_TYPE_ATOM.  May be
 * `NULL`, indicating an empty string.
 *
 * u.integer ::
 * A signed integer, if type is @BDF_PROPERTY_TYPE_INTEGER.
 *
 * u.cardinal ::
 * An unsigned integer, if type is @BDF_PROPERTY_TYPE_CARDINAL.
 */
typedef struct BDF_PropertyRec_ {
    BDF_PropertyType type;
    union {
        const char *atom;
        FT_Int32 integer;
        FT_UInt32 cardinal;
    } u;
} BDF_PropertyRec;


/* *************************************************************************
 *
 * @function:
 * FT_Get_BDF_Charset_ID
 *
 * @description:
 * Retrieve a BDF font character set identity, according to the BDF
 * specification.
 *
 * @input:
 * face ::
 * A handle to the input face.
 *
 * @output:
 * acharset_encoding ::
 * Charset encoding, as a C~string, owned by the face.
 *
 * acharset_registry ::
 * Charset registry, as a C~string, owned by the face.
 *
 * @return:
 * FreeType error code.  0~means success.
 *
 * @note:
 * This function only works with BDF faces, returning an error otherwise.
 */
FT_EXPORT(FT_Error)
FT_Get_BDF_Charset_ID(FT_Face face, const char **acharset_encoding, const char **acharset_registry);


/* *************************************************************************
 *
 * @function:
 * FT_Get_BDF_Property
 *
 * @description:
 * Retrieve a BDF property from a BDF or PCF font file.
 *
 * @input:
 * face ::
 * A handle to the input face.
 *
 * name ::
 * The property name.
 *
 * @output:
 * aproperty ::
 * The property.
 *
 * @return:
 * FreeType error code.  0~means success.
 *
 * @note:
 * This function works with BDF _and_ PCF fonts.  It returns an error
 * otherwise.  It also returns an error if the property is not in the
 * font.
 *
 * A 'property' is a either key-value pair within the STARTPROPERTIES
 * ... ENDPROPERTIES block of a BDF font or a key-value pair from the
 * `info->props` array within a `FontRec` structure of a PCF font.
 *
 * Integer properties are always stored as 'signed' within PCF fonts;
 * consequently, @BDF_PROPERTY_TYPE_CARDINAL is a possible return value
 * for BDF fonts only.
 *
 * In case of error, `aproperty->type` is always set to
 * @BDF_PROPERTY_TYPE_NONE.
 */
FT_EXPORT(FT_Error)
FT_Get_BDF_Property(FT_Face face, const char *prop_name, BDF_PropertyRec *aproperty);

/* */

FT_END_HEADER

#endif /* FTBDF_H_ */


/* END */
